BenchReference / Drill sizes / 6.7 mm 6.7 mm Drill Decimal inches 0.2638″
Millimeters 6.7 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 17/64″ 0.2656″ / 6.747 mm +0.047 mm (+0.0018″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −0.909 mm (−0.0358″)
Letter H 0.2660″ / 6.756 mm +0.056 mm (+0.0022″)
−0.536 mm +0.536 mm 6.7 mm 6.5 mm −0.2 mm 6.6 mm −0.1 mm 6.8 mm +0.1 mm 6.9 mm +0.2 mm 17/64″ +0.047 mm H +0.056 mm ← #1 −0.909 mm tick position = true diameter · metric neighbors above, equivalents below · window ±0.54 mm
Positive difference = cuts a slightly larger hole than 6.7 mm. Sizes
beyond the window are listed with arrows — they are not close substitutes.
Neighboring metric sizes Drill Decimal in mm vs 6.7 mm 6.5 mm 0.2559 6.5 −0.2 mm 6.6 mm 0.2598 6.6 −0.1 mm 6.7 mm 0.2638 6.7 — 6.8 mm 0.2677 6.8 +0.1 mm 6.9 mm 0.2717 6.9 +0.2 mm
← 6.6 mm (smaller) 6.8 mm (larger) →
Compare 6.7 mm with another size
Data provenance. ASME B94.11M, Twist Drills (standard drill size series) (ASME). Millimeter and inch values are converted with the exact definition 1 in = 25.4 mm; the canonical dimension for this metric size is 6.7 mm. See all data sources .